The Holey Dollar & The Dump 1988 Australia’s New Solid Silver Legal Tender Coins. Silver coins, minted and inspected by the Perth Mint. The coins are minted from silver refined to a millesimal purity of 999 parts in 1000. The Holey Dollar contains 1oz of fine silver. The Dump contains 1/40oz of fine silver. Sydney Based Store that has experience in the jewellery industry for over 25 years. All our diamonds have been professionally assessed and examined by diamond experts and gemmologists to ensure authenticity.